Abstract: The objective of this text is to characterize the activities of part-time and substitute teachers and also those of teaching assistants. For this, we chose to use these teachers¿ own words as evidence, through interviews and/or answers provided to a written questionnaire. Our research was focused both on how these teachers experienced their profession, and on how the pedagogical coordinators understood the function of these individuals, in the context of a school institution. Taking a historical-cultural perspective, we went on to analyze this spoken and written language, highlighting elements which emerged in the personal accounts. In the light of psychological studies, these elements became significant to enable a fuller understanding of not only their work, but also the (de)professionalization of these members of the teaching staff